The bodies of three sisters and another relative have been pulled from a submerged car in locks northeast of Kingston. ((CBC))

Police are investigating the circumstances surrounding the deaths of three sisters and another relative who were found inside a submerged car in locks northeast of Kingston.

Ontario Provincial Police divers removed the bodies of three teens, aged 13, 17 and 19, and a 50-year-old woman described as a relative, from a vehicle found in the Kingston Mills locks around 4 p.m. Tuesday. The identities of the victims, who were all from Quebec, have not yet been released.

They had been on vacation in southern Ontario and were on their way back to Quebec, police said Wednesday. They were reported missing by relatives.

"It breaks my heart just saying it," Const. Michael Menor, spokesman for Kingston Police, said in an interview with The Canadian Press.

"You have a family, they've all drowned. It's just horrifyingly tragic."

Menor said investigators do not know what the car was doing in the area.

"It's very very peculiar. There's no rhyme or reason," Menor said. "It's just not an area that anyone would drive their car out to."

Parks Canada employees first noticed the 2004 Nissan Sentra submerged in about five metres of water around 10:30 a.m. and called police.

It took divers more than two hours to get the bodies out.

As part of the probe, police have seized the car and turned it over to mechanics for an inspection to see whether there was a mechanical breakdown or other forensic evidence that might help investigators.

With files from The Canadian Press